Paper orientation for duplexing and collating

Abstract

Method and apparatus for automatically producing a duplexed copy in a document copier machine wherein the leading edge of the rectangular copy sheet is maintained during both passes through the machine and wherein both simplexed and duplexed copies may be collated. This method and apparatus is especially useful when the leading edge is the narrow dimension of the rectangular copy paper.

What is claimed is: 
     
       1. In a document copier machine wherein an electrostatic image is placed upon a copy sheet at a transfer station and said image is fused to said copy sheet at a fusing station, apparatus for automatically providing duplexed copies comprising: guide means for receiving a simplexed copy sheet from said fusing station and guiding said copy sheet around a 180° bend into a first direction and onto a receiving tray;   first stop means for stopping said copy sheet in said tray;   turnaround means for moving said copy sheet at 90° to said first direction and guiding said sheet around a 180° bend into a duplex bin;   second stop means for stopping said copy sheet in said duplex bin; and   sheet moving means for moving said sheet in said first direction and guiding said sheet around a 180° bend into said transfer station,   whereby a duplexed copy is provided while maintaining the leading edge of the copy sheet constant for both passes through said transfer station.   
     
     
       2. The apparatus of claim 1 including a collator wherein said duplexed sheet passes through said fusing station a second time, and into said receiving tray, an alternate paper path comprising: gate means for altering the paper path provided by said turnaround means so that said sheet is fed by said turnaround means into a collator tray;   third stop means for stopping said sheet in said collator tray; and   second sheet moving means for moving said sheet out of said collator tray around a 180° bend into said collator,   whereby duplexed sheets are stacked in correct numerical order in said collator.   
     
     
       3. The method of automatically making duplexed copies in a copy machine, comprising the steps of: receiving a simplexed copy sheet in a first plane from a fusing station and turning said copy sheet over by guiding it around a 180° bend into a second plane while maintaining the leading edge constant;   moving said copy sheet at 90° in said second plane by selecting a new leading edge;   turning said copy sheet over by guiding it around a 180° bend into a third plane;   moving said copy sheet at 90° in said third plane by selecting the original leading edge; and   turning said copy sheet over and feeding it into said copy machine for copying on the blank side of said sheet,   whereby a duplexed copy is produced while maintaining the original leading edge of the copy sheet for both passes through said copy machine.   
     
     
       4. The method of claim 3 wherein said copy machine includes a collator, further including the steps of: receiving said duplexed copy sheet from said fusing station and turning said copy sheet over by guiding it around a 180° bend into said second plane; and   moving said copy sheet from said second plane into said collator,   whereby duplexed sheets are stacked in correct numerical order in said collator.   
     
     
       5. The method of automatically making duplexed copies in a document copier machine, comprising the steps of: receiving a simplexed copy sheet from a fusing station in said machine and inverting said copy while maintaining the leading edge moving in a first direction;   moving said copy at 90° to said first direction by selecting a new leading edge and inverting said copy;   moving said copy in said first direction and inverting said copy; and   feeding said copy into said machine for copying the second side,   whereby a duplexed copy is produced while maintaining the original leading edge of the copy sheet for both passes through said copy machine.   
     
     
       6. The method claim 5 wherein said machine includes a collator, further comprising the steps of: receiving said duplexed copy from said fusing station;   inverting said copy; and   moving said copy into said collator,   whereby duplexed sheets are stacked in correct numerical order in said collator.